Oil cooler



FIG! Dec. 30, 1969 I HvDHUGGlNS 3,486,489

'OIL COOLER- Filed Feb. 12, 1968 INVENTOR. HOMER D. HUGGINS #fi 444/,JWM ATTORNEYS..-

United States Patent U.S. Cl. 12341.33 7 Claims ABSTRACT OF THEDISCLOSURE An oil cooler for a liquid cooled engine in which thetransmission oil is passed through an elongated oil conduit in a liquidcontaining chamber such as the bottom tank of a radiator with theconduit being tubular and arranged within the chamber in the form of aspiral.

In internal combustion engines it is customary to provide cooling liquidfor the engine which is itself cooled as in an air cooled radiator. Itis also customary to provide an oil cooler for cooling the transmissionoil of the engine externally of the transmission.

One of the features of this invention is to provide an improved oilcooler for an internal combustion engine that is liquid cooled with thecooler being in the form of an elongated conduit in a chamber adapted tocontain the cooling liquid for the engine and with this conduit beingsurrounded by cooling liquid in the chamber when in use and the conduitbeing arranged in a spiral in the chamber and attached between the oillines to pass oil therethroagh.

Other features and advantages of the invention will be apparent from thefollowing description of certain embodiments thereof taken inconjunction with the accompanying drawings. f the drawings:

FIGURE 1 is a front elevational view of a cooling liquid radiator for aninternal combustion engine.

FIGURE 2 is an enlarged fragmentary sectional view taken substantiallyalong line 22 of FIGURE 1.

FIGURE 3 is a front elevational view of the oil cooler conduit or tubeof FIGURE 2.

FIGURE 4 is an enlarged cross sectional view through one embodiment of aconduit.

FIGURE 5 is a view similar to FIGURE 4 but showing a second embodimentof the invention.

FIGURE 6 is a view similar to FIGURE 4 but showing a third embodiment ofthe invention.

FIGURE 7 is a view similar to FIGURE 4 but showing a fourth embodimentof the invention.

The cooling radiator 10 for the internal combustion engine (not shown)is provided'with the usual top fill cap 11, upper tank 12 and bottomtank 13. The two tanks are adapted to contain cooling liquid and areconnected by the usual vertical parallel tubes 14 and parallel spacedhorizontal fins 15 both illustrated semi-diagrammatically in FIGURE 1.

The bottom tank 13 is provided with a front wall 16 and rear wall 17.Extending through the rear wall 17 of the bottom tank 13 are a first oilline 18 leading to the bottom tank or chamber 13 and a second oil line19 leading from the bottom tank 13. Each of the oil lines 18 and 19 areconnected in the usual manner to the transmission oil portion of theengine and one such connecting pipe 20 is illustrated in fragmentarysection in FIGURE 2.

Positioned within the bottom tank 13 is an elongated oil conduit 21 thatis arranged in a spiral and attached between the oil lines 18 and 19 topass oil therethrough.

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As can be seen in FIGURE 2, the conduit 21 is surrounded by coolingliquid in the bottom tank 13 when in use.

The spiral 21 is preferably in the form of a helix as shown in thedrawings and is still more preferably in the form of a flat tube havingsubstantially parallel side surfaces 22 and 23 that are also parallel tothe longitudinal axis of the helix.

As can be seen in FIGURES 2 and 3, the oil conduit 21..wi thin the tank13 is unsupported between its areas of attachment to the two oil lines18 and 19.

In a preferred construction the conduit'21 is divided intoa plurality ofparallel passages illustrated at 24 each pair of which are separated bya dividing wall illustrated at 25. This construction is especiallypreferred when the conduit is in the form of the illustrated flat tube.The parallel passage with dividing wall construction not only providesfor parallel liquid flow through the oil cooler but also strengthens thetube internally.

FIGURE 5 illustrates a second embodiment of the tube construction inwhich each passage 24 is provided with a corrugated fin 26 to divideeach passage 24 into parallel subpassages.

if- In the embodiment of FIGURE 6 that flat tube 27 that forms theconduit does not have a unitary dividing wall 25 as in FIGURES 4 and 5but is divided into the plurality of parallel subpassages by acorrugated fin 26 only.

In the embodiment of FIGURE 7 the single fiat tube 28 contains a largeplurality of parallel subpassages 29 separated from each other by walls30 that are of one piece construction within the tube 28. Each passage29 is provided with strengthening ribs 31. Because the tube 28, walls 30and ribs 31 are all unitary the embodiment of FIGURE 7 can be extrudedand then shaped to the required spiral shape.

As used here, the term spiral is generic to both a helix and other formsof spirals such as the watch spring type.

The oil cooler of this invention has a number of very importantadvantages. The spiral shape of the conduit or tube has a turbulizingefliect on the oil flowing therethrough to improve the heat transferbetween the oil in the tube and the cooling liquid on the outer surfacethereof. Furthermore, the pitch of the spiral can be changed as neededto provide a greater or lesser degree of cooling. Thus, the greater thepitch the less the amount of cooling and the smaller the pitch thegreater the amount of cooling. In addition, because in the preferredconstruction the oil cooler tube is substantially unsupported except atits areas of connection to the oil lines, the tube is free to expand andcontract during temperature changes thereby greatly reducing the chancesof failure.

Having described my invention as related to the embodiments shown in theaccompanying drawings, it is my intention that the invention be notlimited by any of its details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the accompanying claims.

I claim:

1. An oil cooler for a liquid cooled engine, comprising: means formingan liquid containing chamber for the engine cooling liquid; at first oilline leading to said chamber; a second oil line leading from saidchamber; and an elongated oil conduit in said chamber to be contacted bysaid cooling liquid therein, the elongated conduit being arranged in aopen helix of spaced coils and supported substantially only by beingattached between said oil lines to pass oil therethrough, said conduitspaced coils thereby being surrounded on all sides by cooling liquid insaid chamber when in use.

2. The oil cooler of claim 1 wherein said conduit is bendable forchanging the pitch of the spiral and is substantially free of externalsupports between said oil lines.

3. The oil cooler of claim 2 wherein said conduit is in the form of atube having parallel fiat side surfaces that are substantially parallelto the longitudinal axis of the tube helix.

4. The oil cooler of claim 3 wherein said tube is provided with internalwalls dividing the tube into a plurality of parallel passages.

5. The oil cooler of claim 1 wherein said liquid containing chamber is apart of a cooling radiator for the liquid.

6. The oil cooler of claim 5 wherein said radiator has a top and bottomtank interconnected by finned parallel tubes and said oil conduit islocated in the bottom tank.

7. The oil cooler of claim 6 wherein said conduit is in the form of atube having parallel flat side surfaces that are substantially parallelto the longitudinal axis of the tube helix.

References Cited UNITED STATES PATENTS 1/1931 Wiltse 2l0-185 X 1/1934Monroe l163 X 9/1936 Yeager 123196 3/1946 Modine 177 6/1961 Farrell165154 FOREIGN PATENTS 6/1961 Canada. 12/ 1937 Germany.

ROBERT A. OLEARY, Primary Examiner 15 A. W. DAVIS, Assistant ExaminerU.S. CL. X.R.

